A central office (CO) is a physical building used to house communications equipment that provides connections and relay data including voice, video and other information. For example, in the field of telecommunications, such communications equipment may include a telephone exchange or telephone switch, which is a system of electronic components that connects telephone calls. The communications equipment may be connected within the CO using a short distance interface.
The short distance interface may be used to cover distances between communications equipment in the approximate range of 100 meters to 500 meters. The short distance interface may be implemented by different transceivers, such as a small form factor pluggable transceiver (SFP) (e.g., 1 Gigabit per second (Gb/s) to 2.7 Gb/s) for Gigabit Ethernet (GE), a 10G form factor pluggable transceiver (XFP) or a C form-factor pluggable transceiver (CFP) (e.g., for 40GE, optical carrier 768 (OC768), optical transport unit level 3 (OTU3), 100GE, etc.). SFP and XFP transceivers use single wavelength, while CFP may use between 4 wavelengths or 10 wavelengths, since, as data rates increase, a single wavelength cannot handle the data rate requirement due to modulator bandwidth limitation.